1. Field of the Invention
The present invention relates to a decolorized oyster extract concentrate. More particularly, the present invention relates to a decolorized oyster extract concentrate which is excellent in the hue and taste and is valuable as a base or additive of a natural seasoning or as a food.
2. Description of the Prior Art
An oyster extract contains large amounts of flavor components such as glutamic acid and flavor-enhancing components such as glycogen, and an oyster extract obtained by concentrating a soup formed as a by-product in the production of canned oysters is used as a natural seasoning called "oyster sauce". Moreover, since the oyster extract contains ingredients effective for recovering and maintaining functions of the human body, a concentrated and dried product of the oyster extract is marketed as a healthy food.
However, the oyster extract concentrate contains relatively large amounts of black and blackish brown components and has an appearance resembling that of soy sauce or Worcester sauce and therefore, is not suitable for seasoning foods in which coloration is disliked. Furthermore, the concentration containing such black or blackish brown components has a taste or smell not desirable for a seasoning, while gives a bitterness, astringency or scorching smell, and the entire taste of the concentrate is heavy and greasy. Accordingly, the conventional oyster extract is used for cooked foods such as frizzled foods and broiled foods but not used for light-taste foods such as soup, clear soup, boiled foods and salads.
Although various methods for separating such black and blackish brown components from the oyster extract have been examined and tried, since these coloring components are stably dispersed in the liquid, separation by adsorption or the like is very difficult.
In separating and removing the coloring components, it is important that the contents of flavor components or nutrients contained in the oyster extract should not be reduced. A refining agent, such as an adsorbent, capable of satisfying this requirement has not been developed.